Biology GK Questions Quiz-18

Biology GK Questions Quiz-18

Biology Multiple Choice Questions (MCQs) Quiz for State and UPSC Civil Services Examinations. Objective Questions on Biology for competitive examinations.

    341. The concentration of which of the following decreases in anaemia ?

    (1) Haemoglobin
    (2) Collagen
    (3) Hyoglobin 
    (4) Myosin
    Answer:
    341. (1) Anemia is a decrease in number of red blood cells (RBCs) or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin deficiency. Because hemoglobin (found inside RBCs) normally carries oxygen from the lungs to the capillaries, anemia leads to hypoxia (lack of oxygen) in organs. Since all human cells depend on oxygen for survival, varying degrees of anemia can have a wide range of clinical consequences. Iron deficiency is thought to be the most common cause of anaemia globally, although other conditions, such as folate, vitamin B12 and vitamin A deficiencies, chronic inflammation, parasitic infections, and inherited disorders can all cause anaemia.

    342. Which of the following diseases usually spreads through air ?

    (1) Plague 
    (2) Typhoid
    (3) Tuberculosis 
    (4) Cholera
    Answer:
    342. (3) Airborne diseases refers to any diseases which are caused by pathogens and transmitted through the air. These viruses and bacteria can be spread through coughing, sneezing, laughing or through close personal contact. These pathogens ride on either dust particles or small respiratory droplets and can stay suspended in air and or are capable of traveling distances on air currents. Many common infections can spread by airborne transmission at least in some cases, including: Anthrax (inhalational), Chickenpox, Influenza, Measles, Smallpox and Tuberculosis. Tuberculosis (TB) happens to be one of the most leading causes of death in adults from infectious diseases. Around 95 percent of people suffering from this disease are from developing areas in the world. Measles and diphtheria are two diseases found in poverty conditions.

    343. Cereals are a rich source of

    (1) Starch 
    (2) Glucose
    (3) Fructose 
    (4) Maltose
    Answer:
    343. (1) Starch or amylum is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store. It is the most common carbohydrate in the human diet and is contained in large amounts in such staple foods as potatoes, wheat, maize (corn), rice, and cassava. Pure starch is a white, tasteless and odourless powder that is insoluble in cold water or alcohol. It consists of two types of molecules: the linear and helical amylose and the branched amylopectin.

    344. Small Pox is caused by

    (1) Rubeola Virus
    (2) Variola Virus
    (3) Varicella
    (4) Myxovirus
    Answer:
    344. (2) Smallpox was an infectious disease unique to humans, caused by either of two virus variants,
    Variola major and Variola minor. The disease is also known by the Latin names Variola or Variola vera,
    which is a derivative of the Latin varius, meaning “spotted”, or varus, meaning “pimple”. After
    vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the eradication of
    smallpox in 1979. Smallpox is one of two infectious diseases to have been eradicated, the other being
    rinderpest, which was declared, eradicated in 2011.

    345. Respiration process requires

    (1) heat 
    (2) water
    (3) oxygen 
    (4) sunlight
    Answer:
    345. (3) In physiology, respiration (often confused with breathing) is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction. This is in contrast to the biochemical definition of respiration, which refers to cellular respiration: the metabolic process by which an organism obtains energy by reacting oxygen with glucose to give water, carbon dioxide and ATP (energy). Respiratory behavior is correlated to the cardiovascular behavior to control the gaseous exchange between cells and blood. Both behaviors are intensified by exercise of the body. However, respiratory is voluntary compared to cardiovascular activity which is involuntary.

    346. A vitamin requires cobalt for its activity. The vitamin is

    (1) Vitamin B12
    (2) Vitamin D
    (3) Vitamin B2
    (4) Vitamin A
    Answer:
    346. (1) Vitamin B12, vitamin B12 or vitamin B12, also called cobalamin, is a water-soluble vitamin with a key role in the normal functioning of the brain and nervous system, and for the formation of blood. It is one of the eight B vitamins. It is normally involved in the metabolism of every cell of the human body, especially affecting DNA synthesis and regulation, but also fatty acid synthesis and energy production. Vitamin B12 consists of a class of chemically related compounds (vitamers), all of which have vitamin activity. It contains the biochemically rare element cobalt.

    347. Plasma membrane in eukaryotic cells is made up of

    (1) Phospholipid
    (2) Lipoprotein
    (3) Phospholipo-protein
    (4) Phospho-protein
    Answer:
    347. (1) The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic
    molecules and controls the movement of substances in and out of cells. The basic function of the cell
    membrane is to protect the cell from its surroundings. The cell membrane consists primarily of a thin layer of amphipathic phospholipids which spontaneously arrange so that the hydrophobic “tail” regions are isolated from the surrounding polar fluid, causing the more hydrophilic “head” regions to associate with the intracellular (cytosolic) and extracellular faces of the resulting bilayer. This forms a continuous, spherical lipid bilayer. Forces such as van der Waals, electrostatic, hydrogen bonds, and noncovalent interactions, are all forces that contribute to the formation of the lipid bilayer. Overall, hydrophobic interactions are the major driving force in the formation of lipid bilayers.

    348. Which one of the following is also called the ‘power plants’ of the cell ?

    (1) Golgi body
    (2) Mitochondrion
    (3) Ribosome
    (4) Lysosome
    Answer:
    348. (2) In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometer (ìm) in diameter. Mitochondria are sometimes described as “cellular power plants” because they generate most of the cell’s supply of adenosine triphosphate (ATP), used as a source of chemical energy. In addition to supplying cellular energy, mitochondria are involved in other tasks such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth.

    349. What is the chemical name of vinegar ?

    (1) Citric acid
    (2) Acetic acid
    (3) Pyruvic acid
    (4) Malic acid
    Answer:
    349. (2) Vinegar is a liquid substance consisting mainly of acetic acid (CH3CO2H) and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. It is today mainly used in the kitchen as a general cooking ingredient, but historically, as the most easily available mild acid, it
    had a great variety of industrial, medical, and domestic uses, some of which (such as a general
    household cleanser) are still promoted today. Commercial vinegar is produced either by fast or slow
    fermentation processes. Acetic acid has a distinctive sour taste and pungent smell. Besides its production as household vinegar, it is mainly produced as a precursor to polyvinylacetate and cellulose acetate. Although it is classified as a weak acid, concentrated acetic acid is corrosive, and attacks the skin.

    350. Animals living in the three trunks are known as

    (1) Arboreal 
    (2) Volant
    (3) Amphibious 
    (4) Aquaticx
    Answer:
    350. (1) Arboreal means living in trees. In every habitat in which trees are present, animals have evolved to move in them. Some animals may only scale trees occasionally, while others are exclusively arboreal. These habitats pose numerous mechanical challenges to animals moving through them, leading to a variety of anatomical, behavioral and ecological consequences. Arboreal species have behaviors specialized for moving in their habitats, most prominently in terms of posture and gait. Specifically, arboreal mammals take longer steps, extend their limbs further forwards and backwards during a step, adopt a more ‘crouched’ posture to lower their center of mass, and use a diagonal sequence gait. 

    351. What happens to a person who receives the wrong type of blood?

    (1) All the arteries constrict
    (2) All the arteries dialates
    (3) The RBCs agglutinate
    (4) The spleen and lymphnodes deteriorate
    Answer:
    351. (3) Red blood cell agglutination indicates clumping of RBC’s due to cold agglutinins which are most commonly IgM antibodies. These antibodies crosslink red cells, which causes overlapping (arrow) and loss of central pallor. The agglutination leads to reduction in red cell count, elevation in MCH and
    MCV as measured by automated instruments. Hemagglu-tination is when the particles involved are
    red blood cells. The agglutin is called hemagglutinin. In cross-matching, agglutination occurring when
    donor red blood cells and recipient’s serum or plasma are incubated together indicates that the donor blood is incompatible for that particular recipient.

    352. Ringworm is a ....... disease.

    (1) Bacterial 
    (2) Protozoan
    (3) Viral 
    (4) Fungal
    Answer:
    352. (4) Dermatophytosis or ringworm is a clinical condition caused by fungal infection of the skin in humans, pets such as cats, and domesticated animals such as sheep and cattle. The term “ringworm” is a
    misnomer, since the condition is caused by fungi of several different species and not by parasitic worms. The fungi that cause parasitic infection (dermatophytes) feed on keratin, the material found
    in the outer layer of skin, hair, and nails. These fungi thrive on skin that is warm and moist, but may also survive directly on the outsides of hair shafts or in their interiors. In pets, the fungus responsible for the disease survives in skin and on the outer surface of hairs.

    353. Pituitary gland is situated in

    (1) the base of the heart
    (2) the base of the brain
    (3) the neck
    (4) the abdomen
    Answer:
    353. (2) Pituitary gland or hypophysis, is an endocrine gland about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is not a part of the brain. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity (sella turcica) covered by a dural fold (diaphragma sellae). The pituitary is functionally connected to the hypothalamus by the median
    eminence via a small tube called the infundibular stem (Pituitary stalk). The pituitary fossa, in which
    the pituitary gland sits, is situated in the sphenoid bone in the middle cranial fossa at the base of the
    brain. The pituitary gland secretes nine hormones that regulate homeostasis.

    354. From which part of the plant is clove, the commonly used spice, obtained ?

    (1) Fruit 
    (2) Flower bud
    (3) Stem 
    (4) Root
    Answer:
    354. (2) Cloves are the aromatic dried flower buds of a tree in the family Myrtaceae, Syzygium aromaticum. The clove tree is an evergreen that grows to a height ranging from 8–12 m, having large leaves and sanguine flowers in numerous groups of terminal clusters. The flower buds are at first of a pale color and gradually become green, after which they develop into a bright red, when they are ready for collecting. Cloves are harvested when 1.5–2 cm long, and consist of a long calyx, terminating in four spreading sepals, and four unopened petals which form a small ball in the centre.

    355. Chewing gum is made from

    (1) Resin 
    (2) Tannin
    (3) Latex 
    (4) Gum
    Answer:
    355. (3) Chewing gum is a type of gum made of chicle, a natural latex product, or synthetic rubber known as polyisobutylene. Most chewing gums are considered polymers. Sugar-free gum sweetened with xylitol has been shown to reduce cavities and plaque. The sweetener sorbitol has the same benefit, but is only about one-third as effective as xylitol. Xylitol is specific in its inhibition of Streptococcus mutans, bacteria that are significant contributors to tooth decay.

    356. The brain of human adult weighs about

    (1) 1200 – 1300 gm
    (2) 1600 – 2000 gm
    (3) 500 – 800 gm
    (4) 100 – 200 gm
    Answer:
    356. (1) The adult human brain weighs on average about 3 lbs. (1.5 kg) with a volume of around 1130 cubic centimetres (cm3) in women and 1260 cm3 in men, although there is substantial individual variation. Men with the same body height and body surface area as women have on average 100g heavier brains, although these differences do not correlate in any simple way with IQ or other measures of cognitive performance. The human brain has the same general structure as the brains of other mammals, but is larger than any other in relation to body size. Large animals such as whales and elephants have larger brains in absolute terms, but when measured using the encephalization quotient which compensates for body size, the human brain is almost twice as large as the brain of the bottlenose dolphin, and three times as large as the brain of a chimpanzee. Much of the expansion comes from the part of the brain called the cerebral cortex, especially the frontal lobes, which are associated with executive functions such as self-control, planning, reasoning, and abstract thought.

    357. Total number of bones in man is

    (1) 206 
    (2) 266
    (3) 300 
    (4) 306
    Answer:
    357. (1) A typical adult human skeleton consists of 206 bones. The 206 bones of the skeleton provide a
    framework and points of attachment for many of the soft tissues of the body. The number of bones
    changes with age, as multiple ossific nuclei joined by synchondroses fuse into fewer mature bones, a
    process which typically reaches completion in the third decade of life.

    358. Which of the following snakes killed for its beautiful skin has been declared an endangered species ?

    (1) Python
    (2) King Cobra
    (3) Russel’s Viper
    (4) Krait
    Answer:
    358. (3) Russell’s Vipers are highly venomous terrestrial snakes found in India which are known for their dark brown spots and lustrous skin. Russell’s Vipers are protected under the schedule II of Wildlife Protection Act. Russell’s Vipers, although belong to the class reptilila of vertebrates, give birth to young ones instead of laying eggs. Primarily nocturnal in nature, the snake is often responsible for the majority of snakebite incidents.

    359. The colour of the eye depends upon the pigment present in

    (1) cornea 
    (2) iris
    (3) rods 
    (4) cones
    Answer:
    359. (2) Eye colour is a polygenic phenotypic character determined by 2 distinct factors: the pigmentation of the eye’s iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris. In humans, the pigmentation of the iris varies from light brown to black, depending on the concentration of melanin in the iris pigment epithelium (located on the back of the iris), the melanin content within the iris stroma (located at the front of the iris), and the cellular density of the stroma.

    360. The ability of the eye to see in the dark, is due to the production of a purple pigment known as

    (1) Carotene 
    (2) Rhodopsin
    (3) Iodopsin 
    (4) Retinene
    Answer:
    360. (4) Retinene–1 is better known as retinaldehyde or simply retinal and is fundamental in the transduction of light into visual signals in the photoreceptor level of the retina (known as the visual cycle). Retinene–2 is more formally known as dehydroretinaldehyde. The energy of impinging photons will convert retinaldehyde from an 11-cis isomer into an all-trans form. In the retina, this conversion induces a conformational change in the surrounding photopsin protein pigment, leading to signaling through the G protein transducin. Retinaldehyde also forms a part of bacteriorhodopsin, a light-induced proton pump found in some archaea.

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